When a merge would result in a conflict and the user chooses resolve, later when committing, NB is able to tell it is a commit after a merge, so it should also suggest the standard commit messae for merges.
Product Version = NetBeans IDE Dev (Build 20130117-1c2fba4f4903)
Operating System = Windows 7 version 6.1 running on amd64
Java; VM; Vendor = 1.7.0_07
Runtime = Java HotSpot(TM) 64-Bit Server VM 23.3-b01

Let make it clear. Merge message is displayed only sometimes. The order is following:
1) commit message template - if autofill selected in "Load Template" in the right top corner
2) last committed message - if autofill selected in "Recent Messages" in the top right corner
3) last canceled commit message - if you open the dialog and cancel it, then the commit message is stored so you can continue typing and finish it once the dialog is opened again
4) merge commit message
So make sure you really get over 1-3 to 4.

I understand it, but I don't agree with #2 and #3 coming first and I have no experience with #1. A merge should always use the standard message, because that's what it will use in case of no conflict. If one wants to change it, it's a very unlikely exception to the rule.

(In reply to comment #8)
> A merge should always use the standard message, because
> that's what it will use in case of no conflict. If one wants to change it, it's
> a very unlikely exception to the rule.
OK, you're probably more experienced Git user than i am. I will give merge messages the highest priority.